cp's OEIS Frontend

A169464 Number of reduced words of length n in Coxeter group on 19 generators S_i with relations (S_i)^2 = (S_i S_j)^33 = I.

%I A169464 #8 Apr 01 2018 11:20:34
%S A169464 1,19,342,6156,110808,1994544,35901792,646232256,11632180608,
%T A169464 209379250944,3768826516992,67838877305856,1221099791505408,
%U A169464 21979796247097344,395636332447752192,7121453984059539456
%N A169464 Number of reduced words of length n in Coxeter group on 19 generators S_i with relations (S_i)^2 = (S_i S_j)^33 = I.
%C A169464 The initial terms coincide with those of A170738, although the two sequences are eventually different.
%C A169464 Computed with MAGMA using commands similar to those used to compute A154638.
%H A169464 <a href="/index/Rec#order_33">Index entries for linear recurrences with constant coefficients</a>, signature (17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, -153).
%F A169464 G.f. (t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 + 2*t^26 +
%F A169464 2*t^25 + 2*t^24 + 2*t^23 + 2*t^22 + 2*t^21 + 2*t^20 + 2*t^19 + 2*t^18 +
%F A169464 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 + 2*t^10 +
%F A169464 2*t^9 + 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t +
%F A169464 1)/(153*t^33 - 17*t^32 - 17*t^31 - 17*t^30 - 17*t^29 - 17*t^28 - 17*t^27
%F A169464 - 17*t^26 - 17*t^25 - 17*t^24 - 17*t^23 - 17*t^22 - 17*t^21 - 17*t^20 -
%F A169464 17*t^19 - 17*t^18 - 17*t^17 - 17*t^16 - 17*t^15 - 17*t^14 - 17*t^13 -
%F A169464 17*t^12 - 17*t^11 - 17*t^10 - 17*t^9 - 17*t^8 - 17*t^7 - 17*t^6 - 17*t^5
%F A169464 - 17*t^4 - 17*t^3 - 17*t^2 - 17*t + 1)
%t A169464 coxG[{33,153,-17}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Apr 01 2018 *)
%K A169464 nonn
%O A169464 0,2
%A A169464 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009